Q&A - Charles Marsden, Dynamic Ceramic

Materials World magazine
,
30 Apr 2013

A metallurgist by trade, Dr Charles Marsden, Technical Director at Dynamic-Ceramic, UK, is something of a convert when it comes to ceramic materials. 

Tell me about your background in ceramics.
My formal education and training was in metallurgy and mechanical engineering. Having completed my PhD at Imperial College London, I moved to Switzerland to continue work on improving the wear resistance of metallic materials at the École Polytechnique Fédéral de Lausanne (EPFL), before joining Dynamic-Ceramic Ltd (DCL) in 1995. It was during my time here that I really got to know more about ceramics. Most of what I have learnt about ceramics has been done on the job, seeing how ceramics are made and then speaking to and visiting customers all around the world to help solve their wear and corrosion problems.

Dynamic-Ceramic won the IOM3 Gold Medal in 2006 – can you tell me about the work that led to this?
DCL does not have any standard products – everything we manufacture is tailor-made to solve a problem of either wear or corrosion. There was no specific project or component that led to us being awarded the medal, rather that over the years we have engaged with almost every manufacturing sector you can imagine to solve wear and corrosion issues. These issues vary from the exotic, such as Formula 1, all the way through to the slightly less glamorous, such as making bearings that go into sewage farms.

What are the benefits of using ceramics over other materials for such applications?
A good example is components that go into gear pumps, which work with very corrosive and erosive chemicals. Stellite-type materials or other wear and corrosion resistant alloys wear out relatively quickly, whereas ceramic materials, being almost totally inert, are not degraded by the chemical materials. This results in massive cost savings.

Another example is the use of ceramics in high-pressure valve components – just when opening or closing the valve, a jet of high-velocity fluid is produced, which can wear out the valve in a similar way to water-jet cutting. Ceramic materials are extremely hard and wear resistant, and don’t wear out as quickly as metallic materials – even tungsten carbide. In this case, the tungsten carbide’s binder phase – be it a nickel or cobalt binder – is the weak link in the armour of the material. The binder phase is washed out, leading to degradation of the valve seat and plug.

What R&D projects are you currently working on?
We’ve been involved in quite a few TSB and European funded research projects. DCL was the lead partner in the TSB-funded NASTRAC project in conjunction with Loughborough University, MEL Chemicals and Valve Solutions. The aim of the project was to further develop nanoscale zirconia powders and components to improve strength, toughness and hydrothermal ageing resistance, hopefully leading to additional opportunities in the valve and medical sectors. Now the project has finished, DCL is in discussions with the various parties to conclude the work, by increasing powder manufacturing volumes and carrying out further application trials. However, it will be about 12 months until we get some concrete results on the large industrial parts.

How will the results of the project impact industry?
Generally speaking, people are fairly ignorant about ceramics and what technical ceramics can do for them. At DCL we have to lead some of our customers through why they should be using ceramics and advise the best type to use. Getting stronger, tougher and more reliable ceramics makes that process easier. It also means companies using ceramics can save money, and so be more competitive and stay in business. There is no point in having yesterday’s tools to do today’s jobs and expect to be in business tomorrow!

Ceramics cover a wide range of industry applications. Are any of these particularly exciting right now?
There are thousands of different types of ceramics used in many applications, from piezoelectric and electro-ceramics to functional ceramics and engineering ceramics. There are always new applications and a myriad of opportunities out there, but it’s a case of solving a problem in a cost-effective way. Using ceramics also helps the environment as they make industrial processes more efficient, reducing scrap and spare parts. Sectors such as the energy, chemical, and oil and gas industries all have particularly demanding environments, either chemically or in terms of physical flow rates, so these are always good areas for ceramic applications.

Do any ceramic materials lend themselves better to particular applications?
Different ceramics have different physical and chemical properties, so it’s important to tailor the right ceramic to the right application. For example, in an environment where thermal shock is a big issue or where a large temperature range is experienced, you would want to use something like a Technide silicon nitride material, as it has excellent thermal shock characteristics. But in an environment with high mechanical demands and a lot of mechanical shock, then a Technox zirconia type material would be more appropriate.

Where does the greatest demand for ceramics lie?
DCL has doubled in size over the last two years and in the middle of a recession, which clearly shows that there is strong demand out there for our ceramic products. About 70% of what we make is exported and tends to go to the more developed countries. About 50% of exports go to the USA and Canada, and the other 50% into the European Union. In terms of specific industries, that’s harder to say – we deal with a diverse range of companies, from the very small to the very big, but it is always related to wear and corrosion. If it’s corrosion, a lot of our work is within fluid handling systems, but it can also be areas of electronics, for instance companies requiring strong, non-magnetic electrical insulation with high thermal conductivity.

The demand for ceramics will increase as people become more aware of what ceramics can offer. Many people are still relatively ignorant of the capabilities of modern engineering ceramics and are often worried about using them in demanding conditions. They often associate ceramics with being weak and brittle, and it is not until they try, and fail, to break a small 3mm diameter rod of one of our zirconia materials, for instance, that they suddenly see the material’s potential. One of our customers uses a ceramic tube with a wall thickness of less than 10mm as a pressure vessel, internally pressurised up to 20,000psi – something only a remarkably reliable ceramic material could withstand.

Do you see any potential applications for ceramics that don’t already exist?
Everywhere where wear and corrosion or electrical insulation is a problem. There are potential applications out there, but it’s up to us as an industry to try to come up with an economic solution. Ceramic parts are always going to be more expensive than the conventional materials they replace, but the ceramics will last longer and enable a machine to produce a better quality product. Take a plastic bearing that’s working in a corrosive environment – if the temperature or the pressure increases, the plastic is extruded and wears out over time. We can replace that with a ceramic, but we have to make sure that a) it is the correct ceramic and b) it will last long enough for the customer to get a cost benefit. A ceramic part may be 10 times more expensive, but if it lasts 20 times longer, that is an economic solution. One company we supply has saved more than a million pounds every year just by switching to ceramic components.

Do you see the ceramics industry developing further?
Undoubtedly. The market for technical or engineering ceramics will do nothing but increase. However, it is up to manufacturers to get costs down to enable some of the market sectors to grow.

For further information, contact Dr Charles Marsden, charles.marsden@dynacer.com